A Java Web application often uses a SQL Server database. SQL Server now comes bundled with a reporting tool, Reporting Services. RS has generated a lot of attention among developers since it first came on the market about a year ago. It is a full-featured reporting tool that includes a WYSIWYG report editor with scripting/programming capabilities, a delivery engine, and a powerful Web services interface. Using RS makes sense—not only from a cost perspective, but also because of the reduced development and deployment complexities compared with using a third-party vendor. This article explores such an integration scenario.
For detailed explanation and step by step understanding purpose please go through the below URL.
http://www.javaworld.com/javaworld/jw-01-2005/jw-0110-sqlrs.html
Sample Code : 1. First Create a servlet name as GetReportItem..
package com.shekarsana;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.Authenticator;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Enumeration;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import util.ReportAuthenticator;
public class GetReportItem extends HttpServlet
{
private static final long serialVersionUID = 1L;
private final static boolean DEBUG = true;
private final static String REPORT_SERVER_URL = "http://servername/ReportServer";
private final static int BUFFER_SIZE = 2048;
public void init(ServletConfig config) throws ServletException
{
super.init(config);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
doGet(request, response);
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
try
{
String queryString = request.getQueryString();
if (queryString.indexOf("cookie=") == -1)
{
System.out.println("\nGetReportItem - ERROR: No cookie parameter provided. Aborting.");
return;
}
String cookie = queryString.substring(queryString.indexOf("cookie"), queryString.indexOf("&") + 1);
queryString = queryString.replaceAll(cookie, "");
cookie = cookie.substring(cookie.indexOf("=") + 1, cookie.length() - 1);
String urlString = REPORT_SERVER_URL + "?" + queryString;
if (DEBUG)
{
System.out.println("\nGetReportItem - Cookie: " + cookie);
System.out.println("GetReportItem - Query String: " + queryString);
System.out.println("GetReportItem - Send to URL: " + urlString);
}
if (queryString == null)
{
ServletOutputStream responseErrorStream = response.getOutputStream();
responseErrorStream.println("GetReportItem - ERROR: No parameters have been provided.");
responseErrorStream.close();
return;
}
URL url = new URL(urlString);
HttpURLConnection repCon = (HttpURLConnection) url.openConnection();
Authenticator.setDefault(new ReportAuthenticator());
repCon.setRequestMethod("GET");
repCon.setRequestProperty("User-Agent", "Mozilla/5.0");
repCon.setRequestProperty("Cookie", cookie);
repCon.setUseCaches(false);
repCon.setFollowRedirects(false);
// Pipe Report Server's Output to the client using buffered streams.
response.setContentType(repCon.getContentType());
response.setHeader("Content-disposition", repCon.getHeaderField("Content-disposition"));
InputStream repInStream = repCon.getInputStream();
ServletOutputStream clientOutStream = response.getOutputStream();
BufferedInputStream bis = new BufferedInputStream(repInStream);
BufferedOutputStream bos = new BufferedOutputStream(clientOutStream);
byte[] buff = new byte[BUFFER_SIZE];
int bytesRead;
while (-1 != (bytesRead = bis.read(buff, 0, BUFFER_SIZE)))
{
bos.write(buff, 0, bytesRead);
}
bis.close();
bos.close();
repInStream.close();
clientOutStream.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
Step2 : 2. Create a servlet name as ReportRequest.
package com.shekarsana;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import util.ReportAuthenticator;
import util.GetAvailableParameters;
public class ReportRequest extends HttpServlet
{
private final static boolean DEBUG = true;
private final static String REPORT_SERVER_URL = "http://ServerName/ReportServer";
private final static String REPORT_PATH = "%2fMYReports%2f";
private final static String REPORT_ITEM_SERVLET_URL = "http://localhost:8080/SANA/GetReportItem"
private final static int BUFFER_SIZE = 2048;
public void init(ServletConfig config) throws ServletException
{
super.init(config);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
try
{
if(DEBUG)
{
System.out.println("\nInitializing Report Request");
System.out.println("---------------------------");
}
Authenticator.setDefault(new ReportAuthenticator());
// Generate parameter string from request
String parameterString = "rs:Command=Render&rc:Toolbar=false";
// Get the list of parameters that can be defined by the user.
ArrayList availableParams = GetAvailableParameters.getParameters();
Enumeration paramEnum = request.getParameterNames();
String currentParam;
while(paramEnum.hasMoreElements())
{
currentParam = (String)paramEnum.nextElement();
if(availableParams.contains(currentParam))
{
// If parameter is available, add it to the string.
parameterString += "&" + currentParam + "=" + request.getParameter(currentParam);
}
}
String reportName = request.getParameter("reportName");
if(DEBUG)
{
System.out.println("ReportRequest - Parameter String: " + parameterString);
System.out.println("ReportRequest - Report retrieved: " + reportName);
}
if (reportName == null)
{
// Bail out if no report name is found.
ServletOutputStream responseErrorStream = response.getOutputStream();
responseErrorStream.println("ERROR: No report name specified");
responseErrorStream.close();
return;
}
// Establish HTTP POST connection to report server
String urlString = REPORT_SERVER_URL + "?" + REPORT_PATH + reportName;
URL url = new URL(urlString);
HttpURLConnection repCon = (HttpURLConnection)url.openConnection();
repCon.setRequestMethod("POST");
repCon.setDoOutput(true);
repCon.setUseCaches(false);
repCon.setFollowRedirects(false);
repCon.setRequestProperty("User-Agent", "Mozilla/5.0");
repCon.setRequestProperty("Content-type", "application/x-www-form-urlencoded" );
repCon.setRequestProperty("Content-length", Integer.toString(parameterString.length()));
// Send parameter string to report server
PrintWriter repOutStream = new PrintWriter(repCon.getOutputStream());
repOutStream.println(parameterString);
repOutStream.close();
// Pipe Report Server's Output to the client
forwardResponse(repCon, response);
}
catch (Exception e)
{
e.printStackTrace();
// Alert the client there has been an error.
ServletOutputStream responseErrorStream = response.getOutputStream();
responseErrorStream.println("There has been an error. Please check the system log for details.");
responseErrorStream.close();
}
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
// Redirect HTTP GET requests to doPost.
doPost(request, response);
}
private void forwardResponse(HttpURLConnection reportCon, HttpServletResponse clientResponse) throws ServletException, IOException
{
// Take the report server's response and forward it to the client.
String cookie = reportCon.getHeaderField("Set-Cookie");
if(cookie == null)
{
System.out.println("ReportRequest - ERROR: No cookie provided by report server. Aborting.");
return;
}
if(cookie.indexOf(";") != -1)
{
cookie = cookie.substring(0,cookie.indexOf(";"));
}
if(DEBUG)
{
System.out.println("ReportRequest - Cookie: " + cookie);
}
String contentType = reportCon.getContentType();
clientResponse.setContentType(contentType);
clientResponse.setHeader("Content-disposition", reportCon.getHeaderField("Content-disposition"));
InputStream repInStream = reportCon.getInputStream();
ServletOutputStream clientOutStream = clientResponse.getOutputStream();
if(!contentType.equals("text/html"))
{
// Use a buffered stream to send all binary formats.
BufferedInputStream bis = new BufferedInputStream(repInStream);
BufferedOutputStream bos = new BufferedOutputStream(clientOutStream);
byte[] buff = new byte[BUFFER_SIZE];
int bytesRead;
while(-1 != (bytesRead = bis.read(buff, 0, BUFFER_SIZE)))
{
bos.write(buff, 0, bytesRead);
}
bis.close();
bos.close();
}
else
{
/*
* Use a character stream to send HTML to the client, replacing
* references to the reporting server with the GetReportItem
* servlet.
*/
String currentWindow = "";
int itemsFound = 0;
for(int ch;(ch = repInStream.read()) != -1;)
{
if(currentWindow.length() < REPORT_SERVER_URL.length())
{
currentWindow += (char)ch;
}
else if(currentWindow.equalsIgnoreCase(REPORT_SERVER_URL) && (char)ch == '?')
{
itemsFound++;
clientOutStream.print(REPORT_ITEM_SERVLET_URL + "?cookie=" + cookie + "&");
currentWindow = "";
}
else
{
clientOutStream.print(currentWindow.charAt(0));
currentWindow = currentWindow.substring(1) + (char)ch;
}
}
clientOutStream.print(currentWindow);
if(DEBUG)
{
System.out.println("ReportRequest - " + itemsFound + " references to the report server found.");
}
}
repInStream.close();
clientOutStream.close();
}
}
Create Java Classes named as :
GetAvailableParameters and ReportAuthenticator
Structure: 1. util/ GetAvailableParameters
and 2. util/ ReportAuthenticator
In ReportAuthenticator Class we need to provide the Credentials:
private String username = "shekar";
private String password = "Sana";
Thanks
SANA
